A new output buffer for 3.3-V PCI-X application in a 0.13-μm 1/2.5-V CMOS process

An output buffer with low-voltage devices to driver high-voltage signals for PCI-X applications is proposed in this paper. Because PCI-X is a 3.3-V interface, the high-voltage gate-oxide stress is a serious problem to design PCI-X I/O circuits in a 0.13-μm 1/2.5-V CMOS process. The simulation results show that the proposed output buffer can be operated at 133 MHz without causing high-voltage gate-oxide stress problem in the 3.3-V PCI-X interface. Besides, a level converter with only I-V and 2.5-V devices that can converter 0/1-V voltage swing to 1/3.3-V voltage swing is also proposed in this paper. The testchip to verify this new proposed output buffer is now under fabrication. The measured results will be shown in the presentation.